This invention relates to an anti-kink control for an electric cord and in particular to an anti-kink control for an electric cord having flat top and bottom surfaces.
The use of high temperature, flame retardant, electrical cord or cable on small appliances such as electric skillets, kettles and the like is required by both the U.L. in the United States and the C.S.A. in Canada. One type of electric cord that has found acceptability by both the U.L. and C.S.A. for high temperature, flame retardant applications is identified as HPN grade heater cord. The elastomeric insulating jacket of the cord is extruded over the cord's conductors. The three conductive wires of the cord are positioned in the same vertical plane and lie parallel to each other. HPN grade heater cord has generally flat top and bottom surfaces and rounded side surfaces. The flat electrical cord having an HPN insulating jacket, can readily flex in directions that are vertically upward or downward relative to the flat surfaces. However, the cable does not readily flex when moved in a horizontal plane in a direction that is generally 90.degree. to the longitudinal axis of the cable. In most instances with anti-kink devices presently available, a cord when flexed in a horizontal plane, 90.degree. to its longitudinal axis, will develop a sharp bend or radius causing stress on the electrically conductive wires passing through the cord. This stress will eventually result in fatigue of the wires causing premature failure of the cord.
The present invention overcomes the foregoing problem by enabling a flat electric cord to be flexed both vertically upwardly and downwardly and also in a horizontal plane 90.degree. relative to the longitudinal axis of the cord. The durability of the electrical cord has been improved. In the prior art, the cord would fail after 5,000 flexes with a one quarter pound load on the cord. Utilization of the present invention enables the cord to withstand in excess of 10,000 flexes with a one pound load.
As a secondary benefit, since the anti-kink control is molded integral with the jacket of the electrical cord, the anti-kink control also functions as a strain relief for the electric cord.
It is accordingly an object of this invention to form an anti-kink control for an electric cord which effectively enables the cord to be flexed both upwardly and downwardly relative to the top and bottom surfaces thereof and in a horizontal plane 90.degree. relative to the longitudinal axis of the cord.